Shaft-locking mechanism



. (No Model.) 2 SheetsSheet 1.

E. G. GRAWFORDa 'SHAFT LOOKING MECHANISM.

No. 530,580. Patented Dec. 11,1894

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E. G; CRAWFORD. SHAFT LOOKING MECHANISM,

No. 530,580. Patented Dec. 11,1891.

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NITED STATES PATENT OFFICE.

EDWVIN G. CRAWFORD, OF ST. LOUIS, MISSOURI.

SHAFT-LOCKING MECHANISM.

SPECIFICATION forming part of Letters Patent No. 530,580, dated December 11, 1894. Application filed- March 16, 1894- Serial No. 503,930. (No modeL) To all whom it may concern: Be it known that I, EDWIN G. CRAWFORD,

of St. Louis, Missourhhave made a new and mechanisms of which the ordinary pawl-andratchet construction is the most familiar form. Generally speaking it consists in the combination of a shaft bearing a cam that is either integral with said shaft or attached thereto, a box in which said shaft is journaled, a fixed stop, and a wedge thatis used in looking the shaft by being drawn between the shaft-cam and the stop and thereby forcing the shaft tightly against the box either ina lengthwise or crosswise direction according to the form of construction which may be preferred.

In carrying out the improvement, the described elernents may be variously relatively shaped and arranged without departing from the principle of the improvement. What I consider a desirable form is as follows: The shaft-cam is in theform of an eccentric, and the shaft is extended beyond the eccentric to receive a handle or other attachment for rotating the shaft. The box is extended to form or is provided with a circularchamber whose wall is concentric with the shaft journal and constitutes the stop with which the wedge coacts. The wedge in its general form is annular and it is fitted to the box-chamber but has its interior opening arranged eccentrically and fitted to receivethe shaft-cam; and the handle has a shoulder that coacts with a shoulder upon the wedge when the shaft is being rotated, all substantially asis hereinafter set forth and claimed, aided by the annexed drawings, making part of this specification, in which- Figure 1 is a side elevation showing the improvement applied to the shaft of a chainpump fixture, a form of construction to which it is. especially adaptable; Fig. 2, a side elevation of the wed e' Fi 3 an ed e elevation of the wedge; Fig. 4, an elevation, from the point of view of Fig. 1, of the shaft and box; Fig. 5, a section on the line 5-=-5 of Fig.

4.; Fig. 6, a view similar to that of Fig. 4:, but

line,.7'-7 of Fig. 6; Fig. 8, a view similar to that of Fig. 6, but includingthe handle; Fig. 9, a view analogous to thatof Fig. 8, but indicating the handle and wedge in broken lines, and with the parts in the position which they in practice assume when any force tends to reverse the direction of the rotation of the shaft. I

The same letters of reference denote the same parts.

A represents the shaft; B, the shaft-box; O, the wedge, and D the handle.

E, Fig. 1, represents any support for the. shaft-box, and F represents an ordinary sprocket-wheel, such as used in chain-pumps,

attached to the shaft.

The shaft, shaft-box, and handle, are each of the usual form, saving as it is modified or supplemented by the improvement under consideration, and the shaft, while exhibited in connection with a chain-pump fixture, may

be almost any shaft that can be rotated in or. that is at, the outer side of the journal,

and is eccentrically arranged, substantially as shown,with reference to the shaft journal a, to form the shaft-cam, and a is the further extension of the shaft to which the handle is applied when itis desired to rotate the shaft. The extension a is suitably shouldered, substantially as shown, to enable the handle to grip it. When the shaft is otherwise adapted to be driven the portion a may not be needed. In the present instance the portion a is shown arranged eccentrically to the shaft-journal, but this arrangement is not essential as it may be concentric with the shaft-journal. The chamber or receptacle 0 for the wedge is conveniently formed by means of the flange upon the box B. The flange extends, first,

4 radially at b, and then at right angles to such ICC constitutes the stop with which the wedge coacts. y

The shaft-extensioh a, in part at least, is opposite the wall I). Thewedge C encircles the cam a, and it is partly at least, and preferably wholly, within the wall b as shown.

The wedge at its outer surface is fitted to the wall I). The opening 0 in the wedge is eccentrically arranged therein substantially as shown, and the cam a fits the wedge-opening. The shoulder 0 upon the wedge, and

with which the handle-shoulder d coacts, is

, preferably in the form of the lug shown, and

lo the lug preferably projects at c to overhang the wall I).

In operating the device the shaft and the wedge are relatively arranged as shown in Figs. 6, 8, 9that is, when it is desired to r0- r5 tate the shaft, as in the direction indicated by the arrow in Fig. 8, the shaft and wedge are relatively turned as in Figs. 6 and 7, the throw a of the cam a being in the direction of the narrower part c of the wedge. The wedge is now free in the chamber 0 and the shaft is free in the wedge, and the two parts can be jointlyrotated and the shaft continues free because the handle shoulder is now against the wedge-shoulder, and the wedge in consequence is carried around with the shaft and the portions a and c of the cam and the wedge, respectively, preserve the described relative position; but, if it is attempted to reverse the direction of the rotation of the shaft, the parts assume the position substantially indicated in Fig. 9. Owing to the fact that the wedge O has a more extended contact with the wall 2) than the cam a has with the wedge, the wedge does not change its position in the chamber 0, but the shaft tends to turn, and, usually, in practice, owing to more or less rough fitting of the enumerated parts, does turn slightly backward in the wedge. This movement causes the throw a of the cam a to be crowded against a wider portion 6 of the wedge, and in consequence the wedge is forced laterally against the wall I) and the shaftextension and wedge are wedged together, and the further backward rotation of the 5 shaft is prevented; but, on turning the shaft -in a forward direction again, the wedge is loosened in the chamber a, and, as soon as the handle-shoulder encounters the wedgeshoulder, the wedge is carried around as before with the shaft, and the rotation can be maintained indefinitely.

The wall I) that defines the chamber in which the wedge is held, and that constitutes the stop with which the wedge coacts, and '35 against which the wedge is crowded on reversing the shaft, need notnecessarily be a part of, or supported from, the shaft-box, and while I prefer it to be a continuous circular wall, extending entirely around the wedge as shown,-it is not essential, as a portion or portions of the wall maybe omitted without materially impairing its function as a stop to resist the wedge; and, if it is not desired to have the backward rotation of the shaft promptly arrested, almost the entire wall may be dispensed with as a small portion only of the wall may suffice for a stop. The wedge need not be a continuous ring to extend entirely around the shaft-cam, and it may be in sections. 7

I claim 1. In a shaft locking mechanism, the combination with the shaft and its box, of an eccentric on and rotating with the shaft, a fixed stop, a wedge loosely connected with said shaft and operating between the shaft eccentric and the stop, and mechanism whereby when said shaft is turned in one direction the wedge is moved with it and, when the movement of the shaft is reversed, the wedge is jammed against the stop and locks the shaft against rotation; substantially as described.

2. In a shaft locking mechanism, the combination with the shaft and its box, of an eccentric on and rotating with the shaft, a fixed ring or flange concentric with and surrounding the shaft, an annular or disk-like wedge looselyencircling the shaft eccentric and occupying the space between said eccentric and go the ring, and mechanism, whereby, when the shaft is turned in one direction, the wedge is freed from the ring and moves with the shaft, and, when said shaft is turned in the opposite direction, the wedge and shaft are locked together and the wedge is jammed against the ring; substantially as described.

3. In a shaft locking mechanism, the combination with the shaft and its box, of an .eccentric on and rotating with said shaft, a ring or flange concentric with and surround ingthe shaft, an annular or disk-like wedge loosely and eccentrically sleeved upon the shaft eccentric and occupying the space between said eccentricand the ring, a handle on the shaft, and a lug onthe annular wedge, said lug located and adapted to be struck ,by the handle when the shaft is moved in one direction, so as to move the wedge and shaft together, a movement of'the shaft in the oppo- I I0 site direction causingthe eccentric and wedge to move with relation to each other until the wedge isjammed against the ring; substantially as described.

Witness my hand this 12th day of March, I 15 EDWIN G. CRAWFORD. Witnesses:

(1D. MOODY, GEO. Q. THORNTON. 

